While some drugs, such as marijuana, have a distinctive aroma, heroin is often odorless. When it does have a smell, heroin is most commonly described as having a vinegar-like odor. Heroin may smell differently depending on where it came from and what other chemicals are in it. It may also have a different smell if the heroin is snorted, injected or smoked.
Heroin’s vinegar smell results from the way heroin is produced.
Heroin is made from morphine, which comes from the milky sap in the seeds of poppy plants. Morphine is transformed into heroin, a much more potent opioid, by boiling it with the chemical acetic anhydride. A byproduct of this chemical reaction is acetic acid — the chemical that gives vinegar its distinctive smell.
Depending on how extensively heroin is purified, trace amounts of acetic acid often remain behind, giving the drug its characteristic vinegar odor. It’s that scent in heroin, in fact, that drug-sniffing police dogs are trained to detect.
While vinegar is the most common scent associated with heroin, some people say the drug smells like Band-Aids, medicine, kitty litter or vitamins. Additives don’t only change what heroin looks like, but they may account for unique aromas.
Heroin is often mixed, or “cut,” with other unknown chemical substances so drug dealers can stretch their supply and maximize their profit. Common cutting agents include powdered sugar, milk, lactose, talc, vitamin B12, quinine, laxatives, caffeine and acetaminophen (Tylenol).
In recent years, though, dealers have gotten more creative with their cutting agents, creating sinister and sometimes deadly mixes that include diphenhydramine (Benadryl) or potent opioids such as fentanyl and carfentanil, which are hundreds to thousands of times stronger than morphine.
A 2016 study published in the Journal of Psychoactive Drugs examining the characteristics of street heroin in Philadelphia and San Francisco found differing opinions on the substance’s scent.
Some individuals in Philadelphia said the powder heroin in their city, which ranges in color from white to light brown, had no smell. Others described the drug as smelling like opium, chemicals, cat urine, kitty litter or whatever it was cut with, including vitamin B and multivitamins.
In San Francisco, a type of heroin called gunpowder heroin — which is a stickier version of black tar heroin — was described by some as smelling like chocolate. Others said it was odorless.
While most heroin purchased on the East Coast flows into the United States from Colombia, the West Coast’s heroin supply typically comes from Mexico. Different manufacturing processes in these countries likely account for the geographic differences in the smell, color and texture of heroin.
In a 2017 study published in the International Journal of Drug Policy, some people said they could identify fentanyl-laced heroin by both sight and smell.
They claimed that heroin laced with fentanyl has more of a powdery smell than heroin’s typical vinegary, acidic odor — though it’s unclear if this is actually true.
A 30-something Rhode Island man identified only as Carl told drug researchers he believes he can differentiate between pure heroin and heroin laced with fentanyl by its vinegary smell.
“If there’s a vinegary smell, you know that’s dope,” he said. “Fentanyl doesn’t have a smell when you sniff it. It tastes like you’re sniffing Tylenol. But then you’re destroyed afterwards.”
But in truth, there’s no way other than through scientific testing to find out what heroin actually contains.
Others in the study, including a woman named Sheryl with a “particular skill for spotting fentanyl-contaminated heroin” by its color, admitted there’s no real way to know what’s in a batch.
“No. No. You can’t tell,” she told researchers. “When you draw it up into the needle — nope. Can’t even tell.”
People who snort or shoot heroin may also notice a different smell than those who smoke the drug.
Individuals who smoke heroin, which is also known as “chasing the dragon,” have described heroin as smelling like burnt brown sugar, sweet licorice, burnt barbecue sauce, sweet strong coffee and burning Band-Aids. It can also be odorless.